US11124412B2 - Manufacturing method for a micromechanical window structure and corresponding micromechanical window structure - Google Patents

Manufacturing method for a micromechanical window structure and corresponding micromechanical window structure Download PDF

Info

Publication number
US11124412B2
US11124412B2 US16/789,503 US202016789503A US11124412B2 US 11124412 B2 US11124412 B2 US 11124412B2 US 202016789503 A US202016789503 A US 202016789503A US 11124412 B2 US11124412 B2 US 11124412B2
Authority
US
United States
Prior art keywords
coating
recess
undercoating
window structure
micromechanical
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
US16/789,503
Other versions
US20200231433A1 (en
Inventor
Joerg Muchow
Rainer Straub
Stefan Pinter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Priority to US16/789,503 priority Critical patent/US11124412B2/en
Publication of US20200231433A1 publication Critical patent/US20200231433A1/en
Application granted granted Critical
Publication of US11124412B2 publication Critical patent/US11124412B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B7/00—Microstructural systems; Auxiliary parts of microstructural devices or systems
    • B81B7/0032—Packages or encapsulation
    • B81B7/0058—Packages or encapsulation for protecting against damages due to external chemical or mechanical influences, e.g. shocks or vibrations
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
    • B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
    • B81C1/00023—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems without movable or flexible elements
    • B81C1/00103—Structures having a predefined profile, e.g. sloped or rounded grooves
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C1/00—Manufacture or treatment of devices or systems in or on a substrate
    • B81C1/00015—Manufacture or treatment of devices or systems in or on a substrate for manufacturing microsystems
    • B81C1/00261—Processes for packaging MEMS devices
    • B81C1/00317—Packaging optical devices
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2201/00—Specific applications of microelectromechanical systems
    • B81B2201/04—Optical MEMS
    • B81B2201/042—Micromirrors, not used as optical switches
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81B—MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICAL DEVICES
    • B81B2203/00—Basic microelectromechanical structures
    • B81B2203/03—Static structures
    • B81B2203/0369—Static structures characterized by their profile
    • B81B2203/0384—Static structures characterized by their profile sloped profile
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C2201/00—Manufacture or treatment of microstructural devices or systems
    • B81C2201/01—Manufacture or treatment of microstructural devices or systems in or on a substrate
    • B81C2201/0101—Shaping material; Structuring the bulk substrate or layers on the substrate; Film patterning
    • B81C2201/0128—Processes for removing material
    • B81C2201/013—Etching
    • B81C2201/0133—Wet etching
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C2201/00—Manufacture or treatment of microstructural devices or systems
    • B81C2201/01—Manufacture or treatment of microstructural devices or systems in or on a substrate
    • B81C2201/0101—Shaping material; Structuring the bulk substrate or layers on the substrate; Film patterning
    • B81C2201/0128—Processes for removing material
    • B81C2201/0143—Focussed beam, i.e. laser, ion or e-beam
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C2201/00—Manufacture or treatment of microstructural devices or systems
    • B81C2201/01—Manufacture or treatment of microstructural devices or systems in or on a substrate
    • B81C2201/0101—Shaping material; Structuring the bulk substrate or layers on the substrate; Film patterning
    • B81C2201/0147—Film patterning
    • B81C2201/0154—Film patterning other processes for film patterning not provided for in B81C2201/0149 - B81C2201/015
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B81—MICROSTRUCTURAL TECHNOLOGY
    • B81C—PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS
    • B81C2203/00—Forming microstructural systems
    • B81C2203/01—Packaging MEMS
    • B81C2203/0136—Growing or depositing of a covering layer
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
    • G02B1/10—Optical coatings produced by application to, or surface treatment of, optical elements
    • G02B1/14—Protective coatings, e.g. hard coatings
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G02B26/08—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light
    • G02B26/0816—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements
    • G02B26/0833—Optical devices or arrangements for the control of light using movable or deformable optical elements for controlling the direction of light by means of one or more reflecting elements the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD

Definitions

  • the present invention relates to a manufacturing method for a micromechanical window structure and to a corresponding micromechanical window structure.
  • a protective wafer is applied on the wafer including MEMS components, for example by anodic bonding.
  • MEMS components for example by anodic bonding.
  • protective wafers including windows are provided for this purpose. The windows are coated with optically transparent layers.
  • a window plate 12 is inserted into a recess 11 of a substrate 1 with the aid of sealants and/or adhesives, recess 11 including edges 11 a inclined with respect to a front side 4 and a rear side 5 of substrate 1 .
  • a first substrate including micromirror devices is described in European Patent No. EP 1 748 029 A2, on which a second substrate including light-transmitting window elements is attached.
  • a method for manufacturing an optical window device is described in German Patent Application No. DE 10 2012 206 858 A1.
  • a transparent layer is applied onto a substrate including a recess and subsequently deformed.
  • Ultrashort pulse lasers are suitable for deliberately structuring or stripping surfaces; for example, the German Future Prize was awarded for ultrashort pulse lasers (communication retrievable from the page http://www.vditz.de/meldung/yerr-zuashssch-fuer-ukp-laser/).
  • the present invention provides a method for manufacturing a micromechanical window structure, including the steps: providing a substrate, the substrate having a front side and a rear side; forming a first recess on the front side; forming a coating on the front side and on the first recess; and forming a second recess on the rear side, so that the coating is at least partially exposed, whereby a window is formed by the exposed area of the coating.
  • the present invention provides a micromechanical window structure including: a substrate, the substrate having a front side and a rear side, the substrate having a recess area extending from the front side to the rear side; and a window spanning inside the recess area, which is formed of a coating and has the shape of a plane inclined with respect to the front side.
  • the present invention provides a cost-effective method for manufacturing micromechanical window structures on a substrate.
  • a hermetically sealed window is formed, such as may be needed in particular for applications in combination with MEMS components, such as micromirrors.
  • micromechanical window structures manufactured using the method according to the present invention ensure a protection of optical elements, such as micromirrors.
  • the window itself By recessing the window in the substrate, the window itself is also protected against damage.
  • the formation of the first recess is carried out in such a way that a recess surface of the first recess has the shape of a plane inclined with respect to the front side.
  • the optical window is well-suited for allowing light to pass through, for example for the use with micromirrors.
  • the inclination of the window may prevent a first order diffraction reflex from appearing in the center of a micromirror.
  • the formation of the second recess is carried out in such a way that the coating is precisely exposed on the recess surface that has the shape of a plane inclined with respect to the front side. In this way, it may be ensured that the entire window surface is available for allowing light to pass through, for example for the use with micromirrors.
  • the formation of the first recess is carried out with the aid of ultrashort pulse lasers. This ensures a high evenness of the surface of the recess since the removed material does not melt, but directly evaporates and thus no poorly controllable molten mass occurs.
  • the coating is a nitride coating.
  • the coating includes a first undercoating and a second undercoating, the first undercoating being a nitride coating and the second undercoating being an oxide coating.
  • a moth eye structure is formed on the coating. In this way, it is possible to decrease the reflection of the window and to increase the transparency of the window.
  • At least one additional anti-reflection layer is formed on the exposed window area of the coating.
  • the formation of the second recess is carried out by trench etching, KOH etching and/or by milling.
  • the coating is a nitride coating.
  • the coating includes a first undercoating and a second undercoating, the first undercoating being a nitride coating and the second undercoating being an oxide coating.
  • FIGS. 1 a through 1 c show schematic cross-sectional views to explain a manufacturing method for a micromechanical window structure according to a first specific embodiment of the present invention.
  • FIGS. 2 a and 2 b show schematic cross-sectional views to explain a manufacturing method for a micromechanical window structure according to a second specific embodiment of the present invention.
  • FIG. 3 shows a schematic cross-sectional view of a micromechanical window structure according to a third specific embodiment of the invention.
  • FIG. 4 shows a schematic top view of a micromechanical window structure according to one specific embodiment of the related art.
  • FIGS. 1 a through 1 c show schematic cross-sectional views to illustrate a manufacturing method for a micromechanical window structure according to a first specific embodiment of the present invention.
  • a substrate 1 for example a semiconductor substrate, such as a silicon substrate, having a front side 4 and a rear side 5 is provided.
  • a first recess 6 is formed in substrate 1 on front side 4 , for example by KOH etching, trench etching, sand blasting or grinding.
  • first recess 6 may also be formed with the aid of an ultrashort pulse laser.
  • first recess 6 is wedge-shaped, a first recess surface 2 being perpendicular to front side 4 , and a second recess surface 3 being inclined with respect to front side 4 at an angle ⁇ , which is formed between second recess surface 3 and front side 4 .
  • Angle ⁇ is greater than zero, for example between 10° and 60°, in particular between 15° and 45°, and particularly preferably between 20° and 40°. If, as described above, an ultrashort pulse laser is used, it may be ensured in particular that first recess surface 2 and second recess surface 3 have great evenness.
  • first recess surface 2 does not have to be perpendicular to front side 4 .
  • first recess surface 2 may be inclined at an angle ⁇ , which is formed between first recess surface 2 and front side 4 .
  • An inclination of first recess surface 2 may be formed, for example, in that a crystallographic direction of substrate 1 , for example of a silicon substrate, is selected in such a way that a ⁇ 111> crystallographic direction of substrate 1 has an angle of inclination with respect to front side 4 .
  • first recess 6 is not limited to the wedge shape; in particular, first recess 6 may be cuboid, trapezoidal or curved.
  • first recess surface 2 and of second recess surface 3 may be improved by an annealing step using forming gas, such as H 2 , at temperatures above 1000° C.
  • forming gas such as H 2
  • a volume formed between second recess surface 3 and rear side 5 corresponds to a second recess 7 recessed in a method step following later.
  • a coating 8 is formed on front side 4 , first recess surface 2 and second recess surface 3 .
  • the formation of coating 8 may take place, for example, by chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma-enhanced chemical vapor deposition (PECVD), plasma impulse chemical vapor deposition (PICVD), low-pressure chemical vapor deposition (LPCVD) or thermal chemical vapor deposition (TCVD) methods or by thermal oxidation.
  • CVD chemical vapor deposition
  • PVD physical vapor deposition
  • PECVD plasma-enhanced chemical vapor deposition
  • PICVD plasma impulse chemical vapor deposition
  • LPCVD low-pressure chemical vapor deposition
  • TCVD thermal chemical vapor deposition
  • the formation of coating 8 does not have to be limited to these methods and may also take place by other methods or by a combination of multiple methods.
  • Coating 8 is preferably made up of a transparent or translucent material, for example glass or plastic.
  • coating 8 may be a nitride coating, such as a low-pressure (LP) nitride coating.
  • LP low-pressure
  • the material of coating 8 does not have to be limited thereto.
  • a mask 9 is additionally applied, for example in the same process step, and subsequently structured, so that the portion of rear side 5 belonging to second recess 7 is left exposed. If mask 9 is made up of the same material as coating 8 , i.e., coating 8 and mask 9 may be applied in a single work step, time and costs may be saved. However, mask 9 may also be made up of a different material than coating 8 and applied separately.
  • second recess 7 is formed, as shown in FIG. 1 c , in such a way that a material of substrate 1 is removed from coating 8 on second recess surfaces 3 from rear side 5 .
  • a window F which is able to allow light to pass through, is created by coating 8 between first recess 6 and second recess 7 .
  • coating 8 on second recess surface 3 covers the full cross-sectional surface of first recess 6 and of second recess 7 , which is thereby available for the window.
  • recess 7 may take place by trench etching and/or by KOH etching.
  • the formation of recess 7 is not limited to these methods; in particular, the formation of recess 7 may take place by milling, with the aid of a laser, for example an ultrashort pulse laser, or by a combination of these methods. In these cases, the method step of attaching a mask 9 may be dispensed with.
  • a micromechanical window structure according to a first specific embodiment of the present invention is formed, manufactured as recited in claim 1 .
  • a substrate 1 has a front side 4 and a rear side 5 , substrate 1 including a recess area 6 , 7 extending from front side 4 to rear side 5 .
  • a window F which is made up of a coating 8 and has the shape of a plane inclined with respect to the front side, spans inside recess area 6 , 7 .
  • recess area 6 , 7 is cuboid, the lateral surfaces being perpendicular to front side 4 and rear side 5 .
  • Recess 6 , 7 does not have to be cuboid and may in particular have a trapezoidal cross section, a general polygonal cross section or a curved cross section.
  • the coating also extends across first recess surface 2 and across front side 4 .
  • the present invention is not limited to this case; in particular, the coating may be absent on front side 4 .
  • FIGS. 2 a , 2 b show a schematic cross-sectional view to illustrate a manufacturing method for a micromechanical window structure according to a second specific embodiment of the present invention.
  • coating 8 is divided into a first undercoating 8 ′ and a second undercoating 8 ′′, first undercoating 8 ′ first being formed on front side 4 , first recess surface 2 and second recess surface 3 , and thereafter second undercoating 8 ′′ being formed on first undercoating 8 ′.
  • First undercoating 8 ′ and second undercoating 8 ′′ are preferably made up of a transparent or translucent material, for example glass or plastic.
  • first undercoating 8 ′ may be an oxide coating
  • second undercoating 8 ′′ may be a nitride coating, for example an LP nitride coating; however, the material of first undercoating 8 ′ and of second undercoating 8 ′′ does not have to be limited thereto.
  • mask 9 may also be divided into a first sub-mask 9 ′ and a second sub-mask 9 ′′, first sub-mask 9 ′ first being formed on rear side 5 and subsequently second sub-mask 9 ′′ being formed on first sub-mask 9 ′, and subsequently first sub-mask 9 ′ and second sub-mask 9 ′′ being structured in such a way that the portion of rear side 5 belonging to second recess 7 is left exposed.
  • first sub-mask 9 ′ may be made of the same material as first undercoating 8 ′
  • second sub-mask 9 ′′ may be made of the same material as second undercoating 8 ′′, so that first sub-mask 9 ′ may be formed simultaneously with first undercoating 8 ′, and second sub-mask 9 ′′ may be formed simultaneously with second undercoating 8 ′′, whereby time and costs may be saved.
  • first sub-mask 9 ′ and the material of second sub-mask 9 ′′ may differ from the materials of first undercoating 8 ′ and of second undercoating 8 ′′.
  • coating 8 may be made up of a first undercoating 8 ′ and a second undercoating 8 ′′; however, mask 9 may be made up of only one sub-mask.
  • coating 8 may be made up of more than two undercoatings, and mask 9 may be made up of more than two sub-masks, and the number of undercoatings of coating 8 and the number of sub-masks of mask 9 do not have to be the same.
  • second recess 7 is formed in such a way that a material of substrate 1 is stripped from coating 8 on second recess surface 3 from rear side 5 .
  • a window F which is able to allow light to pass through, is created by coating 8 between first recess 6 and second recess 7 .
  • the formation of second recess 7 may take place according to one of the above-mentioned methods.
  • the second specific embodiment includes a first undercoating 8 ′ and a second undercoating 8 ′′, it being possible in particular for first undercoating 8 ′ to be a nitride coating and for second undercoating 8 ′′ to be an oxide coating.
  • FIG. 3 shows a schematic cross-sectional view to illustrate a manufacturing method for a micromechanical window structure according to a third specific embodiment of the present invention.
  • coating 8 in particular a portion of coating 8 formed on second recess surface 3 , is at least sectionally provided with a nanostructured surface.
  • the nanostructured surface may in particular be a moth eye structure 10 .
  • Moth eye structure 10 is made up of small elevations, whose distance may be selected in the order of magnitude of the wavelength range of the light used, whereby it may be achieved that a reflection property of coating 8 is reduced, and light may be better transmitted.
  • At least one further anti-reflection coating may be formed on window F.
  • the at least one anti-reflection coating may be a metal coating, for example, which may have a thickness in the range of several nanometers, a plastic coating, a silicon coating or a similar coating.
  • the formation of the coating may be carried out by sputtering, with the aid of a CVD method or with the aid of a dipping method.

Landscapes

  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Computer Hardware Design (AREA)
  • Micromachines (AREA)

Abstract

A manufacturing method for a micromechanical window structure including the steps: providing a substrate, the substrate having a front side and a rear side; forming a first recess on the front side; forming a coating on the front side and on the first recess; and forming a second recess on the rear side, so that the coating is at least partially exposed, whereby a window is formed by the exposed area of the coatings.

Description

CROSS REFERENCE
The present application is a divisional application of U.S. patent application Ser. No. 15/743,326, filed Jan. 10, 2018, which is a U.S. National Phase of International Application PCT/EP2016/061706, filed May 24, 2016, and claims the benefit under 35 U.S.C. § 119 of German Patent Application No. DE 102015213473.3, filed on Jul. 17, 2015, all of which are hereby incorporated by reference in their entireties.
FIELD
The present invention relates to a manufacturing method for a micromechanical window structure and to a corresponding micromechanical window structure.
BACKGROUND INFORMATION
To protect a wafer including micro-electromechanical (MEMS) components against physical or chemical damage, for example a protective wafer is applied on the wafer including MEMS components, for example by anodic bonding. To protect optical elements, such as micromirrors, protective wafers including windows are provided for this purpose. The windows are coated with optically transparent layers.
A manufacturing method for a device equipped with windows is described in German Patent Application No. DE 10 2013 211 886 A1. As shown in FIG. 4, a window plate 12 is inserted into a recess 11 of a substrate 1 with the aid of sealants and/or adhesives, recess 11 including edges 11 a inclined with respect to a front side 4 and a rear side 5 of substrate 1.
A first substrate including micromirror devices is described in European Patent No. EP 1 748 029 A2, on which a second substrate including light-transmitting window elements is attached.
A method for manufacturing an optical window device is described in German Patent Application No. DE 10 2012 206 858 A1. For this purpose, a transparent layer is applied onto a substrate including a recess and subsequently deformed.
Ultrashort pulse lasers are suitable for deliberately structuring or stripping surfaces; for example, the German Future Prize was awarded for ultrashort pulse lasers (communication retrievable from the page http://www.vditz.de/meldung/deutscher-zukunftspreis-fuer-ukp-laser/).
SUMMARY
According to a first aspect, the present invention provides a method for manufacturing a micromechanical window structure, including the steps: providing a substrate, the substrate having a front side and a rear side; forming a first recess on the front side; forming a coating on the front side and on the first recess; and forming a second recess on the rear side, so that the coating is at least partially exposed, whereby a window is formed by the exposed area of the coating.
According to one further aspect, the present invention provides a micromechanical window structure including: a substrate, the substrate having a front side and a rear side, the substrate having a recess area extending from the front side to the rear side; and a window spanning inside the recess area, which is formed of a coating and has the shape of a plane inclined with respect to the front side.
The present invention provides a cost-effective method for manufacturing micromechanical window structures on a substrate. By exposing a coating, a hermetically sealed window is formed, such as may be needed in particular for applications in combination with MEMS components, such as micromirrors.
Separation of windows and insertion with the aid of sealants or adhesives are dispensed with, whereby the method according to the present invention allows the series production of micromechanical window structures.
The micromechanical window structures manufactured using the method according to the present invention ensure a protection of optical elements, such as micromirrors.
By recessing the window in the substrate, the window itself is also protected against damage.
According to one further specific embodiment of the method according to the present invention, the formation of the first recess is carried out in such a way that a recess surface of the first recess has the shape of a plane inclined with respect to the front side. As a result, the optical window is well-suited for allowing light to pass through, for example for the use with micromirrors. The inclination of the window may prevent a first order diffraction reflex from appearing in the center of a micromirror.
According to one further specific embodiment of the method according to the present invention, the formation of the second recess is carried out in such a way that the coating is precisely exposed on the recess surface that has the shape of a plane inclined with respect to the front side. In this way, it may be ensured that the entire window surface is available for allowing light to pass through, for example for the use with micromirrors.
According to one further specific embodiment of the method according to the present invention, the formation of the first recess is carried out with the aid of ultrashort pulse lasers. This ensures a high evenness of the surface of the recess since the removed material does not melt, but directly evaporates and thus no poorly controllable molten mass occurs.
According to one further specific embodiment of the method according to the present invention, the coating is a nitride coating.
According to one further specific embodiment of the method according to the present invention, the coating includes a first undercoating and a second undercoating, the first undercoating being a nitride coating and the second undercoating being an oxide coating. By combining an oxide coating, which has compressive stress, with a nitride coating, which has tensile stress, it is possible to achieve that the coating is under tensile stress and thereby smoothed.
According to one further specific embodiment of the method according to the present invention, a moth eye structure is formed on the coating. In this way, it is possible to decrease the reflection of the window and to increase the transparency of the window.
According to one further specific embodiment of the micromechanical window structure according to the present invention, at least one additional anti-reflection layer is formed on the exposed window area of the coating.
According to one further specific embodiment of the method according to the present invention, the formation of the second recess is carried out by trench etching, KOH etching and/or by milling.
According to one further specific embodiment of the micromechanical window structure according to the present invention, the coating is a nitride coating.
According to one further specific embodiment of the micromechanical window structure according to the present invention, the coating includes a first undercoating and a second undercoating, the first undercoating being a nitride coating and the second undercoating being an oxide coating.
Further features and advantages of specific embodiments of the present invention are derived from the following description with respect to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1a through 1c show schematic cross-sectional views to explain a manufacturing method for a micromechanical window structure according to a first specific embodiment of the present invention.
FIGS. 2a and 2b show schematic cross-sectional views to explain a manufacturing method for a micromechanical window structure according to a second specific embodiment of the present invention.
FIG. 3 shows a schematic cross-sectional view of a micromechanical window structure according to a third specific embodiment of the invention.
FIG. 4 shows a schematic top view of a micromechanical window structure according to one specific embodiment of the related art.
 DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
In all figures, identical or functionally equivalent elements and devices were denoted by the same reference numerals, unless indicated otherwise. The numbering of method steps is used for the sake of clarity and is, in particular, not intended to imply a certain chronological sequence, unless indicated otherwise. In particular, multiple method steps may also be carried out simultaneously.
FIGS. 1a through 1c show schematic cross-sectional views to illustrate a manufacturing method for a micromechanical window structure according to a first specific embodiment of the present invention.
In a first method step, a substrate 1, for example a semiconductor substrate, such as a silicon substrate, having a front side 4 and a rear side 5 is provided.
In a second method step, a first recess 6 is formed in substrate 1 on front side 4, for example by KOH etching, trench etching, sand blasting or grinding. Preferably, first recess 6 may also be formed with the aid of an ultrashort pulse laser.
According to the first specific embodiment of the present invention, first recess 6 is wedge-shaped, a first recess surface 2 being perpendicular to front side 4, and a second recess surface 3 being inclined with respect to front side 4 at an angle φ, which is formed between second recess surface 3 and front side 4. Angle φ is greater than zero, for example between 10° and 60°, in particular between 15° and 45°, and particularly preferably between 20° and 40°. If, as described above, an ultrashort pulse laser is used, it may be ensured in particular that first recess surface 2 and second recess surface 3 have great evenness.
However, first recess surface 2 does not have to be perpendicular to front side 4. In particular, first recess surface 2 may be inclined at an angle α, which is formed between first recess surface 2 and front side 4. An inclination of first recess surface 2 may be formed, for example, in that a crystallographic direction of substrate 1, for example of a silicon substrate, is selected in such a way that a <111> crystallographic direction of substrate 1 has an angle of inclination with respect to front side 4.
The shape of first recess 6, however, is not limited to the wedge shape; in particular, first recess 6 may be cuboid, trapezoidal or curved.
Additionally, an evenness of first recess surface 2 and of second recess surface 3 may be improved by an annealing step using forming gas, such as H2, at temperatures above 1000° C.
A volume formed between second recess surface 3 and rear side 5 corresponds to a second recess 7 recessed in a method step following later.
In a third method step, a coating 8, as shown in FIG. 1b , is formed on front side 4, first recess surface 2 and second recess surface 3. The formation of coating 8 may take place, for example, by chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma-enhanced chemical vapor deposition (PECVD), plasma impulse chemical vapor deposition (PICVD), low-pressure chemical vapor deposition (LPCVD) or thermal chemical vapor deposition (TCVD) methods or by thermal oxidation. The formation of coating 8, however, does not have to be limited to these methods and may also take place by other methods or by a combination of multiple methods.
Coating 8 is preferably made up of a transparent or translucent material, for example glass or plastic. For example, coating 8 may be a nitride coating, such as a low-pressure (LP) nitride coating. The material of coating 8, however, does not have to be limited thereto.
On rear side 5, a mask 9 is additionally applied, for example in the same process step, and subsequently structured, so that the portion of rear side 5 belonging to second recess 7 is left exposed. If mask 9 is made up of the same material as coating 8, i.e., coating 8 and mask 9 may be applied in a single work step, time and costs may be saved. However, mask 9 may also be made up of a different material than coating 8 and applied separately.
In a fourth method step of the manufacturing method for a micromechanical window structure according to the first specific embodiment of the present invention, second recess 7 is formed, as shown in FIG. 1c , in such a way that a material of substrate 1 is removed from coating 8 on second recess surfaces 3 from rear side 5. By exposing coating 8, a window F, which is able to allow light to pass through, is created by coating 8 between first recess 6 and second recess 7. In particular, coating 8 on second recess surface 3 covers the full cross-sectional surface of first recess 6 and of second recess 7, which is thereby available for the window.
The formation of recess 7 may take place by trench etching and/or by KOH etching. The formation of recess 7, however, is not limited to these methods; in particular, the formation of recess 7 may take place by milling, with the aid of a laser, for example an ultrashort pulse laser, or by a combination of these methods. In these cases, the method step of attaching a mask 9 may be dispensed with.
Furthermore, for example, it is also possible to remove a material of the substrate 1 only from a portion of coating 8 on second recess surfaces 3 from rear side 5.
In this way, as illustrated in FIG. 1c , a micromechanical window structure according to a first specific embodiment of the present invention is formed, manufactured as recited in claim 1. A substrate 1 has a front side 4 and a rear side 5, substrate 1 including a recess area 6, 7 extending from front side 4 to rear side 5. A window F, which is made up of a coating 8 and has the shape of a plane inclined with respect to the front side, spans inside recess area 6, 7. According to the first specific embodiment, recess area 6, 7 is cuboid, the lateral surfaces being perpendicular to front side 4 and rear side 5. Recess 6, 7, however, does not have to be cuboid and may in particular have a trapezoidal cross section, a general polygonal cross section or a curved cross section.
According to the first specific embodiment, the coating also extends across first recess surface 2 and across front side 4. However, the present invention is not limited to this case; in particular, the coating may be absent on front side 4.
FIGS. 2a, 2b show a schematic cross-sectional view to illustrate a manufacturing method for a micromechanical window structure according to a second specific embodiment of the present invention.
In contrast to the manufacturing method for a micromechanical window structure according to the first specific embodiment of the present invention, coating 8 is divided into a first undercoating 8′ and a second undercoating 8″, first undercoating 8′ first being formed on front side 4, first recess surface 2 and second recess surface 3, and thereafter second undercoating 8″ being formed on first undercoating 8′.
First undercoating 8′ and second undercoating 8″ are preferably made up of a transparent or translucent material, for example glass or plastic. For example, first undercoating 8′ may be an oxide coating, and, for example, second undercoating 8″ may be a nitride coating, for example an LP nitride coating; however, the material of first undercoating 8′ and of second undercoating 8″ does not have to be limited thereto.
In contrast to the manufacturing method for a micromechanical window structure according to the first specific embodiment of the present invention, mask 9 may also be divided into a first sub-mask 9′ and a second sub-mask 9″, first sub-mask 9′ first being formed on rear side 5 and subsequently second sub-mask 9″ being formed on first sub-mask 9′, and subsequently first sub-mask 9′ and second sub-mask 9″ being structured in such a way that the portion of rear side 5 belonging to second recess 7 is left exposed.
In particular, first sub-mask 9′ may be made of the same material as first undercoating 8′, and second sub-mask 9″ may be made of the same material as second undercoating 8″, so that first sub-mask 9′ may be formed simultaneously with first undercoating 8′, and second sub-mask 9″ may be formed simultaneously with second undercoating 8″, whereby time and costs may be saved.
The material of first sub-mask 9′ and the material of second sub-mask 9″, however, may differ from the materials of first undercoating 8′ and of second undercoating 8″.
The exemplary specific embodiments of the present invention are not limited to these options. In particular, coating 8 may be made up of a first undercoating 8′ and a second undercoating 8″; however, mask 9 may be made up of only one sub-mask. Moreover, coating 8 may be made up of more than two undercoatings, and mask 9 may be made up of more than two sub-masks, and the number of undercoatings of coating 8 and the number of sub-masks of mask 9 do not have to be the same.
As shown in FIG. 2b , in a further step of the manufacturing method for a micromechanical window structure according to the second specific embodiment of the present invention, second recess 7 is formed in such a way that a material of substrate 1 is stripped from coating 8 on second recess surface 3 from rear side 5. By exposing coating 8, a window F, which is able to allow light to pass through, is created by coating 8 between first recess 6 and second recess 7. The formation of second recess 7 may take place according to one of the above-mentioned methods.
As illustrated in FIG. 2b , in this way a micromechanical window structure according to a second specific embodiment of the present invention is formed, manufactured as recited in claim 1. In contrast to the first specific embodiment, as illustrated in FIG. 1c , the second specific embodiment includes a first undercoating 8′ and a second undercoating 8″, it being possible in particular for first undercoating 8′ to be a nitride coating and for second undercoating 8″ to be an oxide coating.
FIG. 3 shows a schematic cross-sectional view to illustrate a manufacturing method for a micromechanical window structure according to a third specific embodiment of the present invention.
In contrast to the manufacturing method for a micromechanical window structure according to the first specific embodiment of the present invention, coating 8, in particular a portion of coating 8 formed on second recess surface 3, is at least sectionally provided with a nanostructured surface. The nanostructured surface may in particular be a moth eye structure 10. Moth eye structure 10 is made up of small elevations, whose distance may be selected in the order of magnitude of the wavelength range of the light used, whereby it may be achieved that a reflection property of coating 8 is reduced, and light may be better transmitted.
According to one further preferred specific embodiment of the present invention, at least one further anti-reflection coating may be formed on window F. The at least one anti-reflection coating may be a metal coating, for example, which may have a thickness in the range of several nanometers, a plastic coating, a silicon coating or a similar coating. The formation of the coating may be carried out by sputtering, with the aid of a CVD method or with the aid of a dipping method.
Although the present invention has been described above based on preferred exemplary embodiments, it is not limited thereto, but is modifiable in a variety of ways. The present invention may in particular be changed or modified in multiple ways without departing from the core of the present invention.

Claims (7)

What is claimed is:
1. A micromechanical window structure, comprising:
a substrate having a front side and a rear side, the substrate including a recess area extending from the front side to the rear side; and
a window, spanning inside the recess area, which is formed by a coating and has a shape of a plane inclined with respect to the front side, wherein the coating includes a first undercoating and a second undercoating, the first undercoating being a nitride coating and the second undercoating being an oxide coating, and the coating is at least one of: transparent, or translucent;
wherein the recess area includes a surface perpendicular to the front side of the substrate, and a portion of the coating is formed on the surface of the recess area perpendicular to the front side of the substrate.
2. The micromechanical window structure as recited in claim 1, wherein the window is optically transparent.
3. The micromechanical window structure as recited in claim 1, wherein the coating of the window is at least partially exposed by the recess area on the rear side.
4. The micromechanical window structure as recited in claim 1, wherein the window spans the recess area.
5. The micromechanical window structure as recited in claim 1, wherein the coating has a tensile stress.
6. The micromechanical window structure as recited in claim 1, wherein the first undercoating has a tensile stress and the second undercoating has a compressive stress.
7. The micromechanical window structure as recited in claim 6, wherein the coating has a tensile stress.
US16/789,503 2015-07-17 2020-02-13 Manufacturing method for a micromechanical window structure and corresponding micromechanical window structure Active US11124412B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US16/789,503 US11124412B2 (en) 2015-07-17 2020-02-13 Manufacturing method for a micromechanical window structure and corresponding micromechanical window structure

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
DE102015213473.3 2015-07-17
DE102015213473.3A DE102015213473A1 (en) 2015-07-17 2015-07-17 Production method for a micromechanical window structure and corresponding micromechanical window structure
PCT/EP2016/061706 WO2017012746A1 (en) 2015-07-17 2016-05-24 Production method for a micromechanical window structure and corresponding micromechanical window structure
US201815743326A 2018-01-10 2018-01-10
US16/789,503 US11124412B2 (en) 2015-07-17 2020-02-13 Manufacturing method for a micromechanical window structure and corresponding micromechanical window structure

Related Parent Applications (2)

Application Number Title Priority Date Filing Date
US15/743,326 Division US20180194616A1 (en) 2015-07-17 2016-05-24 Manufacturing method for a micromechanical window structure and corresponding micromechanical window structure
PCT/EP2016/061706 Division WO2017012746A1 (en) 2015-07-17 2016-05-24 Production method for a micromechanical window structure and corresponding micromechanical window structure

Publications (2)

Publication Number Publication Date
US20200231433A1 US20200231433A1 (en) 2020-07-23
US11124412B2 true US11124412B2 (en) 2021-09-21

Family

ID=56080403

Family Applications (2)

Application Number Title Priority Date Filing Date
US15/743,326 Abandoned US20180194616A1 (en) 2015-07-17 2016-05-24 Manufacturing method for a micromechanical window structure and corresponding micromechanical window structure
US16/789,503 Active US11124412B2 (en) 2015-07-17 2020-02-13 Manufacturing method for a micromechanical window structure and corresponding micromechanical window structure

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US15/743,326 Abandoned US20180194616A1 (en) 2015-07-17 2016-05-24 Manufacturing method for a micromechanical window structure and corresponding micromechanical window structure

Country Status (5)

Country Link
US (2) US20180194616A1 (en)
JP (1) JP6609032B2 (en)
CN (1) CN107835788B (en)
DE (1) DE102015213473A1 (en)
WO (1) WO2017012746A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102020205190A1 (en) * 2020-04-23 2021-10-28 Robert Bosch Gesellschaft mit beschränkter Haftung Manufacturing method for manufacturing at least one cap device or a cap wafer

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005040885A (en) 2003-07-25 2005-02-17 Sony Corp Hollow structure manufacturing method, MEMS element manufacturing method, and electron beam mask manufacturing method
JP2006106753A (en) 2004-10-05 2006-04-20 Samsung Electro Mech Co Ltd Micro mirror and method of manufacturing the same
EP1748029A2 (en) 2005-07-27 2007-01-31 Samsung Electronics Co., Ltd. Micro-mirror device package and method for fabricating the same
JP2007256419A (en) 2006-03-22 2007-10-04 Brother Ind Ltd Optical scanner, optical scanning device, image display device, retinal scanning image display device, and beam forming method in optical scanner
JP4180780B2 (en) 1999-11-04 2008-11-12 三星電子株式会社 Manufacturing method of MEMS structure capable of wafer level vacuum packaging
US20090116675A1 (en) 2005-12-14 2009-05-07 Yuichi Miyoshi Mems diaphragm structure and method for forming the same
JP2011517626A (en) 2008-03-04 2011-06-16 フラウンホーファー−ゲゼルシャフト ツル フェルデルング デル アンゲヴァンテン フォルシュング エー ファウ Cover for a microsystem and method of manufacturing the cover
US20110188140A1 (en) 2010-01-14 2011-08-04 Reinhold Fiess Micromechanical component, optical device, manufacturing method for a micromechanical component, and manufacturing method for an optical device
JP2011523199A (en) 2008-12-22 2011-08-04 ヘリオス アプライド システムス ピーティーイー エルティーディー 3D mold and process for producing submicron 3D structures using 2D photon lithography and nanoimprint
US20120133004A1 (en) 2010-11-26 2012-05-31 Stefan Pinter Method for producing oblique surfaces in a substrate and wafer having an oblique surface
US20120140306A1 (en) * 2010-11-29 2012-06-07 Stefan Pinter Cover device for a micro-optomechanical component, and manufacturing method for such a cover device
DE102012206858A1 (en) 2012-04-25 2013-10-31 Robert Bosch Gmbh A method of manufacturing an optical window device for a MEMS device
US8830557B2 (en) * 2007-05-11 2014-09-09 Qualcomm Mems Technologies, Inc. Methods of fabricating MEMS with spacers between plates and devices formed by same
DE102013211886A1 (en) 2013-06-24 2014-12-24 Robert Bosch Gmbh A window-mounted optical device cover and a manufacturing method of manufacturing a window-mounted optical device cover
US20150200105A1 (en) 2012-09-28 2015-07-16 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. Production method

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102009011305A1 (en) * 2009-03-02 2010-09-09 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. Back contacting solar cells and methods of making same
US8524139B2 (en) * 2009-08-10 2013-09-03 FEI Compay Gas-assisted laser ablation

Patent Citations (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4180780B2 (en) 1999-11-04 2008-11-12 三星電子株式会社 Manufacturing method of MEMS structure capable of wafer level vacuum packaging
JP2005040885A (en) 2003-07-25 2005-02-17 Sony Corp Hollow structure manufacturing method, MEMS element manufacturing method, and electron beam mask manufacturing method
JP2006106753A (en) 2004-10-05 2006-04-20 Samsung Electro Mech Co Ltd Micro mirror and method of manufacturing the same
EP1748029A2 (en) 2005-07-27 2007-01-31 Samsung Electronics Co., Ltd. Micro-mirror device package and method for fabricating the same
US20090116675A1 (en) 2005-12-14 2009-05-07 Yuichi Miyoshi Mems diaphragm structure and method for forming the same
JP2007256419A (en) 2006-03-22 2007-10-04 Brother Ind Ltd Optical scanner, optical scanning device, image display device, retinal scanning image display device, and beam forming method in optical scanner
US8830557B2 (en) * 2007-05-11 2014-09-09 Qualcomm Mems Technologies, Inc. Methods of fabricating MEMS with spacers between plates and devices formed by same
JP2011517626A (en) 2008-03-04 2011-06-16 フラウンホーファー−ゲゼルシャフト ツル フェルデルング デル アンゲヴァンテン フォルシュング エー ファウ Cover for a microsystem and method of manufacturing the cover
JP2011523199A (en) 2008-12-22 2011-08-04 ヘリオス アプライド システムス ピーティーイー エルティーディー 3D mold and process for producing submicron 3D structures using 2D photon lithography and nanoimprint
US20110188140A1 (en) 2010-01-14 2011-08-04 Reinhold Fiess Micromechanical component, optical device, manufacturing method for a micromechanical component, and manufacturing method for an optical device
US20120133004A1 (en) 2010-11-26 2012-05-31 Stefan Pinter Method for producing oblique surfaces in a substrate and wafer having an oblique surface
DE102010062009A1 (en) 2010-11-26 2012-05-31 Robert Bosch Gmbh Method for producing inclined surfaces in a substrate and wafer with inclined surface
US20120140306A1 (en) * 2010-11-29 2012-06-07 Stefan Pinter Cover device for a micro-optomechanical component, and manufacturing method for such a cover device
DE102012206858A1 (en) 2012-04-25 2013-10-31 Robert Bosch Gmbh A method of manufacturing an optical window device for a MEMS device
US20130285169A1 (en) 2012-04-25 2013-10-31 Robert Bosch Gmbh Method for producing an optical window device for a mems device
US20150200105A1 (en) 2012-09-28 2015-07-16 Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V. Production method
DE102013211886A1 (en) 2013-06-24 2014-12-24 Robert Bosch Gmbh A window-mounted optical device cover and a manufacturing method of manufacturing a window-mounted optical device cover

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
International Search Report dated Aug. 1, 2016, of the corresponding International Application PCT/EP2016/061706 filed May 24, 2016.
The German Future Prize was awarded for ultrashort pulse lasers; http://www.vditz.de/meldung/deutscher-zukunftspreis-fuer-ukp-laser/, Dec. 9, 2013.

Also Published As

Publication number Publication date
CN107835788B (en) 2023-05-16
US20180194616A1 (en) 2018-07-12
WO2017012746A1 (en) 2017-01-26
JP2018526232A (en) 2018-09-13
US20200231433A1 (en) 2020-07-23
DE102015213473A1 (en) 2017-01-19
CN107835788A (en) 2018-03-23
JP6609032B2 (en) 2019-11-20

Similar Documents

Publication Publication Date Title
US9620375B2 (en) Production method
EP3236304B1 (en) A scanning mirror device and a method for manufacturing it
US20130147021A1 (en) Multi-layer substrate structure and manufacturing method for the same
US9618323B2 (en) Method for manufacturing optical interferometer
CN104093552B (en) Method for producing Structured optical part
CN103373701B (en) Method for producing an optical window device for a mems device
WO2005001545A1 (en) Thin film precursor stack for mems manufacturing
US20050275072A1 (en) Package having bond-sealed underbump
US7288464B2 (en) MEMS packaging structure and methods
US11124412B2 (en) Manufacturing method for a micromechanical window structure and corresponding micromechanical window structure
RU2439741C1 (en) Method of making sensitive elements of micromechanical systems
CN104977122A (en) Humidity resistant sensors and methods of making same
JP2018041084A (en) Method for manufacturing micro mechanical device having inclined optical window and micro mechanical device corresponding thereto
US6525352B1 (en) Method to reduce release time of micromachined devices
US6979585B2 (en) Micro-electromechanical system
US10948688B2 (en) Optical circuit switch mirror array crack protection
US20070166958A1 (en) Method of wafer level packaging and cutting
CN104167433A (en) Device comprising a spring and an element suspended thereon, and method for manufacturing same
US11623860B2 (en) Interposer substrate, MEMS device and corresponding manufacturing method
CN112105580B (en) Method for producing a micromechanical device having a tilted optical window and corresponding micromechanical device
US10829365B2 (en) Piezoelectric optical MEMS device with embedded moisture layers
US7348535B2 (en) Metal line structure of optical scanner and method of fabricating the same
CN113056437A (en) Method for producing a microelectromechanical sensor and microelectromechanical sensor
CN101638213A (en) Method for manufacturing microstructure capable of integrating semiconductor process
US10663624B2 (en) Method for creating a nanostructure in a transparent substrate

Legal Events

Date Code Title Description
FEPP Fee payment procedure

Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: FINAL REJECTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE AFTER FINAL ACTION FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS

STPP Information on status: patent application and granting procedure in general

Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT VERIFIED

STCF Information on status: patent grant

Free format text: PATENTED CASE

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 4